Add a "fork" of musl as //fusl.

fusl/src/network/inet_pton.c

+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <ctype.h>
+#include <errno.h>
+#include <string.h>
+
+static int hexval(unsigned c)
+{
+        if (c-'0'<10) return c-'0';
+        c |= 32;
+        if (c-'a'<6) return c-'a'+10;
+        return -1;
+}
+
+int inet_pton(int af, const char *restrict s, void *restrict a0)
+{
+        uint16_t ip[8];
+        unsigned char *a = a0;
+        int i, j, v, d, brk=-1, need_v4=0;
+
+        if (af==AF_INET) {
+                for (i=0; i<4; i++) {
+                        for (v=j=0; j<3 && isdigit(s[j]); j++)
+                                v = 10*v + s[j]-'0';
+                        if (j==0 || (j>1 && s[0]=='0') || v>255) return 0;
+                        a[i] = v;
+                        if (s[j]==0 && i==3) return 1;
+                        if (s[j]!='.') return 0;
+                        s += j+1;
+                }
+                return 0;
+        } else if (af!=AF_INET6) {
+                errno = EAFNOSUPPORT;
+                return -1;
+        }
+
+        if (*s==':' && *++s!=':') return 0;
+
+        for (i=0; ; i++) {
+                if (s[0]==':' && brk<0) {
+                        brk=i;
+                        ip[i&7]=0;
+                        if (!*++s) break;
+                        if (i==7) return 0;
+                        continue;
+                }
+                for (v=j=0; j<4 && (d=hexval(s[j]))>=0; j++)
+                        v=16*v+d;
+                if (j==0) return 0;
+                ip[i&7] = v;
+                if (!s[j] && (brk>=0 || i==7)) break;
+                if (i==7) return 0;
+                if (s[j]!=':') {
+                        if (s[j]!='.' || (i<6 && brk<0)) return 0;
+                        need_v4=1;
+                        i++;
+                        break;
+                }
+                s += j+1;
+        }
+        if (brk>=0) {
+                memmove(ip+brk+7-i, ip+brk, 2*(i+1-brk));
+                for (j=0; j<7-i; j++) ip[brk+j] = 0;
+        }
+        for (j=0; j<8; j++) {
+                *a++ = ip[j]>>8;
+                *a++ = ip[j];
+        }
+        if (need_v4 && inet_pton(AF_INET, (void *)s, a-4) <= 0) return 0;
+        return 1;
+}